1. Field of the Invention
The present invention relates to an information processing apparatus, a synchronization correction method and a computer program.
2. Description of the Related Art
In related art, there is provided a content reproduction system in which, for example between a server and a client device including a communication function conforming to the TCP/IP (Transmission Control Protocol/Internet Protocol), content such as audio or video stored in the server is transferred to the client device (reproduction apparatus) via a network and is reproduced. In the content reproduction system, in general, the client device first requests the server for retrieval of reproducible content and for transmission of a list of the reproducible content and receives the list of the reproducible content transmitted from the server in response to the request. Furthermore, the client device requests the server for transmission of content selected from the list described above by a user and can reproduce the content transmitted from the server in response to the request, while receiving the content.
At this time, the client device sequentially temporarily stores (buffers) content data streamed from the server in a buffer memory and when a predetermined amount of data is stored in the buffer memory, the client device reads out the content data from the buffer memory and starts reproduction. Moreover, in the case where the client device only supports uncompressed digital data, the server, for example, decodes (expands) compressed digital data which has been compressed and encoded by an encoding system such as the MP3 (MPEG Audio Layer3), converts the data into, for example, linear PCM data which is uncompressed data and transmits the data to the client device.
In the content reproduction system described above, a plurality of client devices can be connected to a network and the plurality of client devices can receive the same content from the server and can synchronously reproduce it. For example, when a party is held at a user's home, a home network system including a client device set in a living room and a client device set in a bedroom may be used in a form in which the client devices in the living room and the bedroom synchronously reproduce the same music content.
As a method for realizing synchronous reproduction by a plurality of client devices, there is disclosed a technology in which a server simultaneously distributes the same content to a plurality of client devices by using a multicast (e.g., UDP (User Datagram Protocol) multicast) and the plurality of client devices synchronously reproduce the content (e.g., JP-A-2006-237918). In this case, in order to realize the synchronous reproduction with high accuracy, it is necessary to notify each of the client devices of a reproduction timing, and in the aforementioned JP-A-2006-237918, the server (e.g., HDD recorder) performs time management (calculation, notification and the like of the reproduction timing) for performing the synchronous reproduction. Moreover, there is also disclosed a content reproduction system to easily realize synchronous reproduction which does not need a specified router for connecting devices and which also can be performed through wireless connection, without performing the time management on the server side nor the slave terminal (client terminal) side (e.g., refer to JP-A-2008-160518).